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2020.05.05 Tuesday

Acidic / neutral / alkaline pH

Today is Children's Day.
So for elementary school students.
Reposted content of an experiment in a school lab in 2009.

Acidic / neutral / alkaline.
BTB is complicated to dispense. The litmus test paper is difficult to see the subtle differences.
Therefore, I experimented with a solution made by boiling red cabbage and Gynura bicolor. 

[red cabbage solution]from the left
hydrochloric acid/Aqueous sodium hydroxide solution/Aqueous sodium chloride solution/Boric acid water/Soapy water/Calcium hydroxide solution/vinegar/Sugar water/Carbonated water/Tap water/rain water/Purple cabbage solution
Purple cabbage solution


[Gynura bicolor solution]from the left
hydrochloric acid/Aqueous sodium hydroxide solution/Aqueous sodium chloride solution/Boric acid water/Soapy water/Calcium hydroxide solution/vinegar/Sugar water/Carbonated water/Tap water/rain water/Gynura bicolor solution Gynura bicolor solution

23:55 | scientifique | - | - | |
2020.04.20 Monday

Hypochlorous Acid Water is not a sodium hypochlorite

It's been a few months since the alcoholic disinfectant became difficult to obtain due to the epidemic of COVID-19.
Recently, "Hypochlorous Acid Water" is one of the disinfecting solutions that replaces alcohol, which is beginning to attract a lot of attention.
However, this "Hypochlorous Acid Water", at the present time (April 20, 2020), it seems that it is unknown as to how effective it is against the new coronavirus at the research stage.
However, since alcoholic disinfectant is not available, this "Hypochlorous Acid Water" is in short supply, and it seems that it is becoming difficult to obtain it recently.

But be careful!
The point is that there are products that are sold as "Hypochlorous Acid Water" even though they are made differently from the correct method for producing "Hypochlorous Acid Water."
Although the aqueous solution sold as "Hypochlorous Acid Water" can be used for sterilization, there are some products that may cause adverse effects on the human body depending on the method of use.
We must thoroughly check the safety data for the chemical components used in the raw materials!

However, in any case, "Hypochlorous Acid Water" is currently difficult to obtain.
Of course, there are people who say, “If we can't buy it, we can make it ourselves.” Recently, it seems that several kinds of products called “Hypochlorous Acid Water generator” are sold.
This generator claims that if we put water and salt into a bottle and press the switch, electrolysis will start and "Hypochlorous Acid Water" will be completed in a few minutes.

We often see products that can  not know which "Hypochlorous Acid Water" or "Sodium Hypochlorite" is produced.
However there is a big difference between the two. They are  different materials!
"Hypochlorous Acid Water" is acidic and has less rough hands and environmental impact. On the other hand, "Sodium Hypochlorite" is alkaline, and even if it is diluted and used, it will chap our hands, and it has a large environmental load, and trihalomethanes (some of which are toxic and carcinogenic) are also generated.

In addition, "Sodium Hypochlorite" is the same as diluted chlorine-based bleach for kitchen (about 200 yen/ 600mL) that can be bought at convenience stores.
Wipe the doorknob etc. with a cloth containing "500mL plastic bottle filled with water and 1 cup of plastic bottle cap chlorine-based bleach for kitchen" (a solution of chlorine-based bleach for kitchen diluted to 0.01-1% with water). It was introduced on TV as a disinfection method that can be done at home.
It is very dangerous if it is not sufficiently diluted with water. 

In fact, the other day (April 2020), there was a patient in Zhengzhou, Henan Province, China, who had a white frosted glass shadow on his lungs. The white shadow of the lungs is the same as that of a covid-19 infected person...! The hospital was in a tumult. However, in reality, it seems that the fact that "Sodium Hypochlorite" was taken into the body due to excessive disinfection without diluting it caused toxic gas, resulting in pneumonia.

Ladies and gentlemen, please do not buy malicious products.


23:55 | scientifique | - | - | |
2019.08.28 Wednesday

Practice

The sad news is that "effort surpasses talent" was a lie.
Associate Professor Brooke Macnamara of Case Western Reserve University in Ohio and Megha Maitra have researched and are published in the Royal Society's open science online science journal.

URL https://royalsocietypublishing.org/doi/10.1098/rsos.190327

In 1993, a research by psychologist Ericsson who studied the relationship between practice time and ability of violinists, a first-class violinist was practicing 10,000 hours by the age of 20, so people were born with It was concluded that 10,000 hours of practice could excel at something more than talent, and it later led to the "rule of 10,000 hours" that became a topic in various fields.
However, in a study reproduced by Macnamara 26 years later, the time spent practicing accounted for about one-fourth of the difference in ability, and there was a bias in the research method in 1993. It was decided that there was an error including this.
Mr. Ericsson and others seem to argue against this, but it is said that the exercise time is not the whole thing, but the genetics, environmental factors, quality of practice, support of the surroundings, etc. are all important.

Of course, I haven't practiced 10,000 hours by the age of 20.
The longer practice, the more accurate and the less likely we are to make a mistake. However, I couldn't play very well in public performance. This was not limited to the harp, but the piano. And there were people who had the same experience as me. What we have in common is that  practice at a certain place such as own home, and that we can play perfectly at home, but when we change places, we cannot play.
It's my personal feeling, but if I continue to play the same song at the same place, I'll feel like playing with the spinal reflex, rather than my brain. I'm not sure why I can play without looking at the score. But I can play correctly. However, when I changed the playing position, the score suddenly disappeared from my mind and my body did not move as I expected. It's a tragedy!
On the other hand, I had the experience that when I couldn't practice much, I was able to concentrate more in the public performance and went well.
As a matter of fact, it is difficult to change the practice place because the piano and harp are not easy to carry around. So rather than practicing in the same place for 2 hours, I think it's better to divide it into 4 times of 30 minutes each. There may be differences depending on whether the song is easy or difficult. If there is any research around that, I would like to know a lot.


23:55 | scientifique | - | - | |
2019.03.31 Sunday

Scyphocrinus

 

スキフォクリニテス  
Scyphocrinites sp. Excavated in Morocco. Lived during the Silurian and Devonian periods. An extinct genus of crinoids.
… I can't memorize everything lol.
Surprisingly, this seems to be real, not a replica.

He had a floating bag and was in a floating life. There is a mouth on the stem, and it is like a petal stretched around it and prey on the bait in the sea. Somehow the number of things like petals is a multiple of 5.


23:56 | scientifique | - | - | |
2019.03.31 Sunday

Anomalocaris

 

アノマロカリス
About 515 million years ago, an sea animal that lived in the Cambrian period. Excavated in Kangaroo Island, Australia. Arthropod compound eyes.

This is not also a replica. Collection of South Australian Museum.
Anomalocaris has the appearance of adding fungi and shrimp and dividing it by two, and is said to have been 60 cm to 2 m long. It seems that they used trilobite as their staple food. I'm not sure what part of this fossil is.


23:55 | scientifique | - | - | |
2019.01.07 Monday

Partial solar eclipse

20190107partial solar eclipse
Although the magnitude of eclipse was not so big this time, when max magnitude of eclipse, I felt cold. But that's probably just my imagination because the temperature doesn't seem to change much during a total solar eclipse.
It seems that a partial solar eclipse will be seen in various parts of Japan on December 26th this year, but I heard that the eclipse that can be observed in Tokyo is slightly smaller than this time.
If it is an annular solar eclipse, it can be observed in Hokkaido in 2030. 11 years left.


23:55 | scientifique | - | - | |
2018.09.05 Wednesday

Le risque aviaire

鳥と航空機が衝突する、いわゆるバードストライクは後を絶たないが、それを回避すべく、鳥を追い払う自律型ドローンの技術が確立されつつある。
IEEE Xploreのwebサイトに、この報告書が掲載されている。この研究は、アメリカの工学者にしてアニメーション・プログラマである、クレイグ・レイノルズ(Craig Raynolds)が考案し作製した、鳥の群れが動くモデルを基に、インペリアル・カレッジ・ロンドンとカリフォルニア工科大学、KAIST(Korea Advanced Institute of Science and Technology)の研究者たちが、アメリカ国立科学財団(National Science Foundation, NSF)のcareer awardを得て進められている。



動画の25秒目あたりがシミュレーション画面で、青い三角形が鳥、緑色が次の到達地点、赤が追跡者で、鳥の群れのリーダーを追跡して方向転換させている。続く実際の動画を見ても、1機のドローンが鳥の群れを追い払うことに見事に成功している。

現状では、各地の空港で鳥を追い払うための訓練をされた犬やハヤブサを導入したり、爆竹を鳴らす、鳥が嫌がる音を流すなどの策が講じられ、銃の規制が緩めの国では散弾銃の空砲を鳴らすケースもあるとの事。 これまでラジコン飛行機を活用したケースはあるようだが、これだけ身近な存在になってきているドローンが、このような分野でも活用されていくのは自然な流れであろう。
ただ、風の日は難しいだろうなあ。


20:00 | scientifique | - | - | |
2018.08.30 Thursday

色が変わる朝顔

團十郎朝顔八重咲の朝顔
今年の七夕に朝顔市で入手した團十郎朝顔と八重咲の朝顔。8月半ば頃は全く咲かなくなっていたのに、涼しくなり始めた頃から再び咲き始め、いつも目を楽しませてくれる。

昨日も、蕾が2つ並んでいた。
朝顔(前日の蕾)
色が薄桃色なので、その色の花が翌朝に咲くものだと思っていた。
しかし、翌朝見ると…
朝顔(翌朝)
予想に反して、薄い青色の花が2輪開花していた。
さらに、夕方見てみると…
朝顔(翌日の夕方)
昨夕の蕾と同じ薄桃色に変化しているではないか。

花の細胞のpHは刻々と変化しており、花弁の表面細胞の液胞に含まれるアントシアニンがリトマス紙のように反応して色が変化したのであろう(花弁の細胞は1個が約40μmの大きさで、それに極細の針を刺してpHを測定した実験もある!)。
しかし、この鉢植えを買ってから今日までの55日間、毎日花を見ていたが、色が変化する朝顔が咲いたのはこれが初めてだ。

朝顔の色の変化について、おもしろい動画を見つけたので貼っておく。

20:00 | scientifique | - | - | |
2018.08.25 Saturday

筑紫恋し

 もう8月も下旬だというのに、今年はツクツクボウシの鳴き声が殆ど聴こえてこないのはなぜだろう。
結構あちこち移動しているのだが、8/5に港区で1回、8/15に目黒区で1回と、8/25に練馬区で3回聴いただけである。おそらく、合計で3〜4匹だ。
 今夏はそれほどレアであるにも関わらず、先ほど某W校の構内を歩いていたら、"W"字型の模様でお馴染みのツクツクボウシが道端に落ちているではないか。寿命が尽きて間もないのか、損傷もなくきれいな形を留めていたので、連れて帰ってきてしまった。

ツクツクボウシ♀20180825

 体長3cm程度の♀。翅脈の黒っぽい点の数からも、ヒグラシではなくツクツクボウシであろう。
 九州にいた頃は、ツクツクボウシは夏休みの終わり頃に大合唱していたように記憶しているが、東京にはあまりいないのか、または、今年の気候が厳しかったのか。ネット検索しても同様の声はなさそうなので、気のせいかもしれない。

 ところで、ツクツクボウシには「筑紫恋し」という別名があるらしい。
出処は、小泉八雲(1850-1904)の"Shadowings"(1900)の "Sémi" 。

 ところが或る人は、この音はツクシコヒシだと言ふ。古昔筑紫の人が遠國で病氣の爲め死んで、その魂魄が一匹の秋蝉となつたもので、それてツクシコヒシ、ツクシコヒシ(『筑紫慕はし!筑紫見たし!』)と絶え間無しに叫ぶのだといふ伝説がある。

この「筑紫の人」の性別が分からない。筑紫の姫だという記述もどこかで見たが、この部分の英語版によると男性だということになる↓

But some say that the sound is Tsukushi-koïshi. There is a legend that in old times a man of Tsukushi (the ancient name of Kyûshû) fell sick and died while far away from home, and that the ghost of him became an autumn cicada, which cries unceasingly, Tsuhushi-koïshi ! — Tsuhushi-koïshi ! ("I Iong for Tsukushi ! — l want to see Tsukushi !" )

 今度は、一次資料、即ち、この"伝説"の出処が分からないので調べてみたが、結局分からずじまいである。
小泉八雲はどこでこの伝説を知ったのだろうか。福岡に伝わる伝説なのか、或いは、福岡から見た遠国にある言い伝えなのか。

21:00 | scientifique | - | - | |
2018.06.26 Tuesday

羽化するヤゴ


(2008/6/26録画)
偶然にも、ちょうど10年前の今日録画した映像を見つけたので、記念に貼ってみました。
数百倍速に編集したので、画質は粗いです。
スマホでは表示されません。

05:00 | scientifique | - | - | |

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